This invention relates to a hinge assembly capable of turnably connecting a device main body and a cover together in a notebook type personal computer, an electronic dictionary or the like and stopping the cover in an optional closed position.
In general, a hinge assembly of this type has one pair of hinge members. The pair of hinge members are non-turnably connected to the device main body and the cover and turnably connected to each other. By this, the device main body and the cover are turnably connected together.
The hinge assembly includes a movable member connected to one of the hinge members such that the movable member is non-turnable but movable in a direction of an axis of rotation. A friction member is disposed between this movable member and the other hinge member. The friction member is press contacted with the other hinge member and the movable member by a coiled spring (biasing means) for biasing the movable member towards the other hinge member side. Accordingly, when the pair of hinge members are about to turn or are being turned, a frictional resistance corresponding in size to the biasing force of the coiled spring is generated between the other hinge member and the movable member. This frictional resistance is set larger than a rotational torque of the cover caused by its dead weight. Accordingly, the cover can be stopped in an optional open position (see Japanese Utility Model Publication No. H07-47579).
In the above-mentioned conventional hinge assembly, since a coiled spring is used in order to obtain a frictional resistance for stopping the cover, there is involved such a problem that the hinge assembly is increased in size to that extent. Moreover, the coiled spring used as a biasing means is difficult to keep its biasing force at a fixed level and the biasing force tends to be greatly fluctuated. Accordingly, the frictional resistance caused by the frictional member becomes irregular at every hinge assembly. As a result, a turning resistance of the cover becomes irregular at every notebook type personal computer.